Example embodiments of the inventive concept relate to apparatus and method for treating a substrate, and in particular, to apparatus and method for treating a substrate using two or more types of treatment solutions.
To fabricate a semiconductor device or a liquid crystal display device, it is necessary to perform several processes (such as photolithography, etching, ashing, ion-implantation, thin-film deposition, and cleaning processes) on a substrate. By performing the etching process on a thin layer (e.g., a metal, oxide, poly-silicon, or photoresist layer) formed on the substrate, it is possible to form patterns with desired shapes.
The etching process may be classified into two method; wet and dry etching method. In the case of the wet etching method, the substrate or the thin layer is etched using a treatment solution, and in the case of the dry etching method, the substrate or the thin layer is etched using plasma or ion beam.
Generally, the wet etching method may include a step of supplying an etching solution on a center region of a rotating substrate. Owing to a centrifugal force, the etching solution supplied on the center region of the substrate is spread on the entire region of the substrate. However, the etching process may suffer from non-uniformity in etch rate; for example, an under- or over-etched region may be formed on the substrate. In the case where the substrate is over-etched, an oxide layer may be formed on the over-etched region of the substrate.
To overcome this issue, referring to FIG. 1, an etching process may be further performed to etch an edge region of the substrate W; for example, an etching solution may be supplied on the edge region of the substrate W. However, during the process of etching the edge region, the center region of the substrate W may be dried, and this may lead to formation of damaged patterns. In addition, the etching solution supplied to the edge region of the substrate W may be partially scattered toward the center region of the substrate W, and this may lead to a process failure.